He listed some topics he would prefer talking about and
called the birth-certificate question "a long, complex subject
that I just don't like talking about, and I won't talk about it."

Host Chuck Todd pressed Trump a second time on the issue, but the
businessman dodged again, insisting he wanted to talk about
things like the economy.

"I just don't discuss it," Trump said. "And really it hasn't been
brought up for a long time."

The exchange follows Trump's
latest campaign-trail controversy: At a Thursday town-hall
event, he sparked criticism from his rivals, the White
House, and parts of the media by declining to correct a supporter
who called Obama a Muslim foreigner.

His campaign initially said he didn't fully hear the supporter,
but Trump argued Saturday that he shouldn't be
"morally obligated" to defend Obama.

He repeated that argument during his "Meet the Press"
interview.

"So this man got up, and he felt very strongly — whoever he was —
he felt very, very strongly and very powerfully about something,"
Trump recalled. "And whether we all agree with it or not, it
wasn't my obligation to defend [Obama]."

Trump further said there is a "severe problem" with some Muslims.

"I feel strongly that Muslims are excellent. I know so many
Muslims that are such fabulous people," he said. "But there is a
problem. I mean, there's no question about it. And we can be
politically correct, and we can say there is no problem
whatsoever. But the fact is there is a problem with some. And
it's a very severe problem."

Donald Trump on "Meet the Press."NBC/

Todd also asked Trump if he would support a Muslim for president.
Retired neurosurgeon Ben Carson, another leading Republican
contender, said on the same program that he "would not
advocate that we put a Muslim in charge of this nation,
according to The Associated Press. But Trump seemed unsure.

"I can say that it's something that at some point could happen.
We'll see. It's something that could happen. Would I be
comfortable? I don't know if we have to address it right now. But
I think it is certainly something that could happen," Trump said.

Referencing conspiracy theorists who question Obama's faith,
Trump added that "some people have said it already happened,
frankly."

However, he told Todd that he would take Obama "at his word" that
he's a Christian.

Several years ago, Trump was one of the most prominent people
challenging the authenticity of Obama's birth certificate. But
since he announced his presidential campaign this year, Trump
insists he's
"off that subject."

"I mean, you're bringing it up this morning," he said Sunday.
"But I'm into the world of jobs. I'm into the world of military
and vets, and, frankly, I discuss Obamacare because [with]
Obamacare, you see what's happening with the premiums. They're
going through the roof. A lot of problems with Obamacare."